A ferroelectric memory has been said to be an ideal memory because of its outstanding characteristic property of a high access speed comparable to that of a DRAM, and yet it is non-volatile and capable of operating with a lower power consumption. It has a capacitor of ferroelectric material such as Pb(ZrxTi1-x)O3 (PZT) and SrBi2Ta2O3 (SBT) which are oxides with a perovskite-type crystal structure, so that it records information by means of the direction of its remanent polarization.
The ferroelectric oxide needs in its production a process of heat treatment for crystallization in an oxygen atmosphere which is carried out after its thin film has been formed. Consequently, the electrodes through which electrical signals are transmitted to the ferroelectric thin film as a capacitor are made of a noble metal, such as Pt and Ir, which is chemically stable and resistant to oxidation and deterioration at high temperature during heat treatment. For example, Japanese Patent Laid-open No. Hei 9-102590 discloses a ferroelectric capacitor composed of PZT (for the ferroelectric thin film) and Pt (for the electrode).